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Router Lab

This tutorial explains the shape of examples/router-lab.yaml. It is a compact router configuration that demonstrates the resources routerd is growing around.

The example is not meant to be pasted blindly onto a production host. Interface names, prefixes, credentials, and upstream behavior are environment-specific.

Topology​

The lab model uses:

  • wan: upstream Ethernet interface
  • lan: downstream Ethernet interface
  • DHCPv4 on WAN
  • DHCPv6-PD on WAN
  • static IPv4 on LAN
  • dnsmasq for LAN DHCP/DNS/RA
  • DS-Lite tunnel resources
  • default route policy with health checks

Validate And Inspect​

routerd validate --config examples/router-lab.yaml
routerd plan --config examples/router-lab.yaml

The plan should show DNS/DHCP service only on the configured LAN interface. A server must list the interfaces it serves through listenInterfaces; scopes are rejected if they bind to an interface the server did not explicitly allow.

DHCP And DNS​

The lab config uses:

kind: IPv4DHCPServer
spec:
  server: dnsmasq
  managed: true
  listenInterfaces:
    - lan

For IPv6, dnsSource: self selects the delegated LAN address such as pd-prefix::3. dnsmasq advertises that DNS server through DHCPv6 and RA RDNSS, which is important for Android clients.

NTP And Syslog​

The lab also demonstrates local system resources:

kind: NTPClient
spec:
  provider: systemd-timesyncd
  managed: true
  source: static
  interface: wan
  servers:
    - pool.ntp.org

When interface is set, routerd renders the NTP server onto that systemd networkd link. LogSink can send local routerd events to syslog locally or to a remote syslog endpoint.

Apply Carefully​

On a real host:

sudo /usr/local/sbin/routerd reconcile \
  --config /usr/local/etc/routerd/router.yaml \
  --once \
  --dry-run

Only remove --dry-run after you have verified that routerd will not take over interfaces still owned by cloud-init or another network manager.